How to use push_back() and pop_back() vector functions in C++
The push_back() function
The push_back() function is used to insert an element at the end of a vector. This function is available in the <vector> header file.
Parameters
The push_back() function accepts one parameter, val, which specifies the value inserted at the end of the vector.
Return value
The push_back() function does not return anything.
Code
Now, let’s see the code and see how the push_back() function is used:
#include <iostream>#include <vector>using namespace std;int main() {vector<int> vec = {1,2,3};cout << "Original Vector: ";for(int x: vec)cout << x << " ";vec.push_back(5);vec.push_back(10);cout << "\nVector after pushing some values: ";for(int x: vec)cout << x << " ";return 0;}
Explanation
- In lines 1 and 2, we import the required packages.
- In lines 6 and 9, we create a vector that contains integers, and print the elements.
- In lines 11 and 12, we call the
push_back()function and insert some integer values. - In lines 13 and 15, we create and print the elements of the vector. We can see that the elements have been added at the end of the vector.
The pop_back() function
The pop_back() function is used to remove the last element from the vector. This function is available in the <vector> header file.
Parameters
The pop_back() function does not accept any parameters.
Return value
The pop_back() function does not return anything.
Code
Now, let’s look at the code and see how to use the pop_back() function:
#include <iostream>#include <vector>using namespace std;int main() {vector<int> vec = {1,2,3,4,5,6,7};cout << "Original Vector: ";for(int x: vec)cout << x << " ";vec.pop_back();vec.pop_back();cout << "\nVector after popping some values: ";for(int x: vec)cout << x << " ";return 0;}
Explanation
- In lines 1 and 2, we import the required packages.
- In lines 6 and 9, we create a vector that contains integers and print the elements.
- In lines 11 and 12, we call the
pop_back()function and insert some integer values. - In lines 13 and 15, we create and print the elements of the vector. We can see that two elements have been removed from the last of the vector.